diff --git a/doc/image-guide/source/introduction.rst b/doc/image-guide/source/introduction.rst index 5dcecc578a..d31739189b 100644 --- a/doc/image-guide/source/introduction.rst +++ b/doc/image-guide/source/introduction.rst @@ -24,17 +24,47 @@ that has a bootable operating system installed on it. Virtual machine images come in different formats, some of which are described below. -Raw - The ``raw`` image format is the simplest one, and is natively - supported by both KVM and Xen hypervisors. - You can think of a raw image as being the bit-equivalent of - a block device file, created as if somebody had copied, say, - ``/dev/sda`` to a file using the :command:`dd` command. +AKI/AMI/ARI + The `AKI/AMI/ARI + `_ + format was the initial image format supported by Amazon EC2. + The image consists of three files: - .. note:: + AKI (Amazon Kernel Image) + A kernel file that the hypervisor will load initially to boot the image. + For a Linux machine, this would be a ``vmlinuz`` file. - We do not recommend creating raw images by dd'ing block device - files, we discuss how to create raw images later. + AMI (Amazon Machine Image) + This is a virtual machine image in raw format, as described above. + + ARI (Amazon Ramdisk Image) + An optional ramdisk file mounted at boot time. + For a Linux machine, this would be an ``initrd`` file. + +ISO + The `ISO + `_ + format is a disk image formatted with the read-only ISO 9660 (also known + as ECMA-119) filesystem commonly used for CDs and DVDs. + While we do not normally think of ISO as a virtual machine image format, + since ISOs contain bootable filesystems with an installed operating system, + you can treat them the same as you treat other virtual machine image files. + +OVF + `OVF `_ + (Open Virtualization Format) is a packaging format for virtual machines, + defined by the Distributed Management Task Force (DMTF) standards group. + An OVF package contains one or more image files, a .ovf XML metadata file + that contains information about the virtual machine, and possibly other + files as well. + + An OVF package can be distributed in different ways. For example, + it could be distributed as a set of discrete files, or as a tar archive + file with an ``.ova`` (open virtual appliance/application) extension. + + OpenStack Compute does not currently have support for OVF packages, + so you will need to extract the image file(s) from an OVF package + if you wish to use it with OpenStack. QCOW2 The `QCOW2 `_ @@ -55,22 +85,17 @@ QCOW2 Because raw images do not support snapshots, OpenStack Compute will automatically convert raw image files to qcow2 as needed. -AMI/AKI/ARI - The `AMI/AKI/ARI - `_ - format was the initial image format supported by Amazon EC2. - The image consists of three files: +Raw + The ``raw`` image format is the simplest one, and is natively + supported by both KVM and Xen hypervisors. + You can think of a raw image as being the bit-equivalent of + a block device file, created as if somebody had copied, say, + ``/dev/sda`` to a file using the :command:`dd` command. - AMI (Amazon Machine Image) - This is a virtual machine image in raw format, as described above. + .. note:: - AKI (Amazon Kernel Image) - A kernel file that the hypervisor will load initially to boot the image. - For a Linux machine, this would be a ``vmlinuz`` file. - - ARI (Amazon Ramdisk Image) - An optional ramdisk file mounted at boot time. - For a Linux machine, this would be an ``initrd`` file. + We do not recommend creating raw images by dd'ing block device + files, we discuss how to create raw images later. UEC tarball A UEC (Ubuntu Enterprise Cloud) tarball is a gzipped tarfile that @@ -82,11 +107,6 @@ UEC tarball Ubuntu cloud solution that has been replaced by the OpenStack-based Ubuntu Cloud Infrastructure. -VMDK - VMware ESXi hypervisor uses the - `VMDK `_ - (Virtual Machine Disk) format for images. - VDI VirtualBox uses the `VDI `_ @@ -103,27 +123,7 @@ VHDX which has some additional features over VHD such as support for larger disk sizes and protection against data corruption during power failures. -OVF - `OVF `_ - (Open Virtualization Format) is a packaging format for virtual machines, - defined by the Distributed Management Task Force (DMTF) standards group. - An OVF package contains one or more image files, a .ovf XML metadata file - that contains information about the virtual machine, and possibly other - files as well. - - An OVF package can be distributed in different ways. For example, - it could be distributed as a set of discrete files, or as a tar archive - file with an ``.ova`` (open virtual appliance/application) extension. - - OpenStack Compute does not currently have support for OVF packages, - so you will need to extract the image file(s) from an OVF package - if you wish to use it with OpenStack. - -ISO - The `ISO - `_ - format is a disk image formatted with the read-only ISO 9660 (also known - as ECMA-119) filesystem commonly used for CDs and DVDs. - While we do not normally think of ISO as a virtual machine image format, - since ISOs contain bootable filesystems with an installed operating system, - you can treat them the same as you treat other virtual machine image files. +VMDK + VMware ESXi hypervisor uses the + `VMDK `_ + (Virtual Machine Disk) format for images.